Pith Number

pith:2BJ4PEUS

pith:2009:2BJ4PEUS5JC7RT4SZIBLIVJ5L5

not attested not anchored not stored refs pending

Cohomological rigidity and the number of homeomorphism types for small covers over prisms

Xiangyu Cao, Zhi L\"u

arxiv:0903.3653 v3 · 2009-03-23 · math.GT · math.AT · math.CO

Open paper page JSON Open Graph Bundle Merged state What is a Pith Number?

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{2BJ4PEUS5JC7RT4SZIBLIVJ5L5}

Prints a linked badge after your title and injects PDF metadata. Compiles on arXiv. Learn more

Record completeness

1 Bitcoin timestamp

2 Internet Archive

3 Author claim open · sign in to claim

4 Citations open

5 Replications open

✓ Portable graph bundle live · download bundle · merged state

The bundle contains the canonical record plus signed events. A mirror can host it anywhere and recompute the same current state with the deterministic merge algorithm.

Receipt and verification

First computed	2026-05-18T04:28:20.506020Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

d053c79292ea45f8cf92ca02b4553d5f7a50f8e256b60744586ca91c33b6b925

Aliases

arxiv: 0903.3653 · arxiv_version: 0903.3653v3 · doi: 10.48550/arxiv.0903.3653 · pith_short_12: 2BJ4PEUS5JC7 · pith_short_16: 2BJ4PEUS5JC7RT4S · pith_short_8: 2BJ4PEUS

Agent API

Resolver JSON Graph JSON Events JSON Schema Signing key

Verify this Pith Number yourself

curl -sH 'Accept: application/ld+json' https://pith.science/pith/2BJ4PEUS5JC7RT4SZIBLIVJ5L5 \
  | jq -c '.canonical_record' \
  | python3 -c "import sys,json,hashlib; b=json.dumps(json.loads(sys.stdin.read()), sort_keys=True, separators=(',',':'), ensure_ascii=False).encode(); print(hashlib.sha256(b).hexdigest())"
# expect: d053c79292ea45f8cf92ca02b4553d5f7a50f8e256b60744586ca91c33b6b925

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "f5668e8ce6f2a1f07263f93d4bd297a586fa35e2c8ca45c85905394ed4a1a13d",
    "cross_cats_sorted": [
      "math.AT",
      "math.CO"
    ],
    "license": "http://creativecommons.org/licenses/by/3.0/",
    "primary_cat": "math.GT",
    "submitted_at": "2009-03-23T18:50:36Z",
    "title_canon_sha256": "44caad0e61984d685b63ef56d7fc8b972ae9ee7991cf8abc1f47067569d30880"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0903.3653",
    "kind": "arxiv",
    "version": 3
  }
}